Term: charge-transfer (CT) transition
https://doi.org/10.1351/goldbook.C01008

Definition:
An electronic transition in which a large fraction of an electronic charge is transferred from one region of a molecular entity, called the electron donor, to another, called the electron acceptor (intramolecular CT) or from one molecular entity to another (intermolecular CT). Typical for donor-acceptor complexes or multichromophoric molecular entities. In some cases the charge-transfer absorption band may be obscured by the absorption of the partners.

Related Terms:
1) electron donor (http://doi.org/10.1351/goldbook.E01988).
2) electron acceptor (http://doi.org/10.1351/goldbook.E01976).
3) intramolecular (http://doi.org/10.1351/goldbook.I03130).
4) intermolecular (http://doi.org/10.1351/goldbook.I03098).

Source: PAC, 1996, 68, 2223. 'Glossary of terms used in photochemistry (IUPAC Recommendations 1996)' on page 2232 (https://doi.org/10.1351/pac199668122223)

Citation: 'charge-transfer (CT) transition' in IUPAC Compendium of Chemical Terminology, 5th ed. International Union of Pure and Applied Chemistry; 2025. Online version 5.0.0, 2025. https://doi.org/10.1351/goldbook.C01008

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